<template>
	<!-- 分类选项卡 -->
	<view class="category-tabs-wrap">
		<!-- 吸顶 -->
		<view class="u-sticky-wrap" :class="[elClass]" :style="{ height: fixed ? height + 'px' : 'auto', backgroundColor: isSticky ? '#fff' : '#f6f6f6' }">
			<view
				class="u-sticky"
				:style="{ position: fixed ? 'fixed' : 'static', top: stickyTop + 'px', left: left + 'px', width: width == 'auto' ? 'auto' : width + 'px', zIndex: 1109 }"
			>
				<view class="tabs-wrap u-p-y-20" :style="isSticky ? 'border-bottom:1px solid #eee;background-color:#fff' : ''">
					<scroll-view scroll-x class="tabs-content" scroll-with-animation :scroll-left="scrollLeft">
						<view class="u-flex u-row-cetner u-flex-1 u-col-center">
							<view class="tab-item u-flex-col u-col-center u-row-center" v-for="(item, index) in tabsList" :key="index" @tap="tabChange(index)">
								<view class="tab-title u-m-y-6" :class="{ 'title-active': tabCur == index }">{{ item.name }}</view>
								<view class="tab-des" :class="{ 'des-active': tabCur == index }">{{ item.description }}</view>
							</view>
						</view>
					</scroll-view>
				</view>
			</view>
		</view>

		<!-- 瀑布流 -->
		<view class="u-waterfall u-p-16" v-if="styleType == 1">
			<view id="u-left-column" class="u-column">
				<view class="goods-item u-m-b-16 u-flex u-row-center u-col-center" v-for="leftGoods in leftList" :key="leftGoods.id">
					<shopro-goods-card
						:detail="leftGoods"
						:type="leftGoods.activity_type || ''"
						:image="leftGoods.image"
						:title="leftGoods.title"
						:subtitle="leftGoods.subtitle"
						:price="leftGoods.price"
						:originPrice="leftGoods.original_price"
						:tagTextList="leftGoods.activity_discounts_tags"
						@click="$Router.push({ path: '/pages/goods/detail', query: { id: leftGoods.id } })"
					></shopro-goods-card>
				</view>
			</view>
			<view id="u-right-column" class="u-column">
				<view class="goods-item u-m-b-16 u-flex u-row-center u-col-center" v-for="rightGoods in rightList" :key="rightGoods.id">
					<shopro-goods-card
						:detail="rightGoods"
						:type="rightGoods.activity_type || ''"
						:image="rightGoods.image"
						:title="rightGoods.title"
						:subtitle="rightGoods.subtitle"
						:price="rightGoods.price"
						:originPrice="rightGoods.original_price"
						:tagTextList="rightGoods.activity_discounts_tags"
						@click="$Router.push({ path: '/pages/goods/detail', query: { id: rightGoods.id } })"
					></shopro-goods-card>
				</view>
			</view>
		</view>

		<!-- m -->
		<view class="big-card-wrap u-p-10" v-if="styleType == 2">
			<block v-for="item in goodsList" :key="item.id">
				<sh-goods-card
					:detail="item"
					:type="item.activity_type || ''"
					:image="item.image"
					:title="item.title"
					:subtitle="item.subtitle"
					:price="item.price"
					:originPrice="item.original_price"
					:sales="item.sales"
					:tagTextList="item.activity_discounts_tags"
					@click="$Router.push({ path: '/pages/goods/detail', query: { id: item.id } })"
				></sh-goods-card>
			</block>
		</view>

		<view class="x-c" style="width: 100%;">
			<!-- 缺省页 -->
			<shopro-empty v-if="isEmpty" marginTop="200rpx" :image="$IMG_URL + '/imgs/empty/empty_goods.png'" tipText="暂无该商品，还有更多好货等着你噢~"></shopro-empty>

			<!-- 更多 -->
			<u-loadmore v-show="!isEmpty" height="80rpx" :status="loadStatus" icon-type="flower" color="#ccc" />
		</view>
	</view>
</template>

<script>
/**
 * category-tabs
 * @description 一个可以吸顶的分类列表
 * @property {Boolean} enable = false - 是否吸顶,tabbar项中，组件不会自动销毁，需要自行开关
 * @property {Array} tabsList  - 分类列表
 * @property {Array | Number} styleType  - 卡片类型
 */
let systemInfo = uni.getSystemInfoSync();
// #ifdef MP-WEIXIN || MP-BAIDU || MP-TOUTIAO || MP-QQ
let menuButtonInfo = uni.getMenuButtonBoundingClientRect();
// #endif
import shGoodsCard from '../components/sh-goods-card.vue';
export default {
	components: {
		shGoodsCard
	},
	data() {
		return {
			// 吸顶相关
			fixed: false,
			height: 'auto',
			elClass: this.$u.guid(),
			left: 0,
			width: 'auto',
			stickyTop: 0,
			isSticky: false, //是否吸顶

			// 瀑布流 350-330
			addTime: 100, //排序间隙时间
			leftHeight: 0,
			rightHeight: 0,
			leftList: [],
			rightList: [],
			tempList: [],

			tabCur: 0,
			scrollLeft: 0,
			isEmpty: true,
			categoryId: this.tabsList[0]?.id,
			goodsList: [],
			tabCurrent: 0,
			loadStatus: 'loadmore', //loadmore-加载前的状态，loading-加载中的状态，nomore-没有更多的状态
			currentPage: 1,
			lastPage: 1
		};
	},
	watch: {
		enable(val) {
			if (val == false) {
				this.fixed = false;
				this.disconnectObserver('contentObserver');
			} else {
				this.initObserver();
			}
		}
	},
	props: {
		tabsList: {
			type: Array,
			default: () => []
		},
		styleType: {
			type: [String, Number],
			default: 1
		},
		enable: {
			type: Boolean,
			default: false
		}
	},
	created() {
		this.getGoodsList();
		// 触底监听
		uni.$on('uOnReachBottom', data => {
			if (this.currentPage < this.lastPage) {
				this.currentPage += 1;
				this.getGoodsList();
			}
		});
	},
	mounted() {
		this.initObserver();
	},
	beforeDestroy() {
		this.disconnectObserver('contentObserver');
	},
	methods: {
		// 瀑布流相关
		async splitData() {
			if (!this.tempList.length) return;
			let item = this.tempList[0];
			if (!item) return;

			// 分左右
			if (this.leftHeight < this.rightHeight) {
				this.leftHeight += item.activity_discounts_tags.length ? 350 : 330;
				this.leftList.push(item);
			} else if (this.leftHeight > this.rightHeight) {
				this.rightHeight += item.activity_discounts_tags.length ? 350 : 330;
				this.rightList.push(item);
			} else {
				this.leftHeight += item.activity_discounts_tags.length ? 350 : 330;
				this.leftList.push(item);
			}

			// 移除临时列表的第一项，如果临时数组还有数据，继续循环
			this.tempList.splice(0, 1);
			if (this.tempList.length) {
				setTimeout(() => {
					this.splitData();
				}, this.addTime);
			}
		},
		clear() {
			this.leftList = [];
			this.rightList = [];
			this.leftHeight = 0;
			this.rightHeight = 0;
			this.tempList = [];
		},

		// 吸顶相关
		initObserver() {
			if (!this.enable) return;
			// #ifdef APP-PLUS || H5
			this.stickyTop = systemInfo.statusBarHeight + 44;
			// #endif
			// #ifdef MP
			let height = systemInfo.platform == 'ios' ? 44 : 48;
			let top = systemInfo.statusBarHeight + height;
			this.stickyTop = systemInfo.statusBarHeight + height;
			// #endif
			this.disconnectObserver('contentObserver');

			this.$uGetRect('.' + this.elClass).then(res => {
				this.height = res.height;
				this.left = res.left;
				this.width = res.width;
				this.$nextTick(() => {
					this.observeContent();
				});
			});
		},
		observeContent() {
			this.disconnectObserver('contentObserver');
			const contentObserver = this.createIntersectionObserver({
				thresholds: [0.95, 0.98, 1]
			});
			contentObserver.relativeToViewport({
				top: -this.stickyTop
			});
			contentObserver.observe('.' + this.elClass, res => {
				if (!this.enable) return;
				this.setFixed(res.boundingClientRect.top);
			});
			this.contentObserver = contentObserver;
		},
		setFixed(top) {
			const fixed = top < this.stickyTop;
			if (fixed) {
				this.isSticky = true;
			} else if (this.fixed) {
				this.isSticky = false;
			}
			this.fixed = fixed;
		},
		disconnectObserver(observerName) {
			const observer = this[observerName];
			observer && observer.disconnect();
		},

		// 商品列表
		getGoodsList() {
			let that = this;
			that.$http('goods.lists', {
				category_id: that.categoryId,
				page: that.currentPage
			}).then(res => {
				if (res.code === 1) {
					that.goodsList = [...that.goodsList, ...res.data.data];
					that.tempList = res.data.data;
					that.isEmpty = !that.goodsList.length;
					that.lastPage = res.data.last_page;
					that.loadStatus = that.currentPage < res.data.last_page ? 'loadmore' : 'nomore';
					that.splitData();
				}
			});
		},

		// tabs
		tabChange(index) {
			this.tabCur = index;
			this.scrollLeft = (index - 1) * 60;
			this.categoryId = this.tabsList[index].id;
			this.styleType === 1 && this.clear();
			this.goodsList = [];
			this.currentPage = 1;
			this.lastPage = 1;
			this.loadStatus = 'loadmore';
			this.getGoodsList();
		}
	}
};
</script>

<style lang="scss" scoped>
@mixin vue-flex($direction: row) {
	/* #ifndef APP-NVUE */
	display: flex;
	flex-direction: $direction;
	/* #endif */
}
.category-tabs-wrap {
	min-height: 1000rpx;
	// 吸顶
	.u-sticky-wrap {
		background-color: #fff;
	}
	// 瀑布流
	.u-waterfall {
		@include vue-flex;
		flex-direction: row;
		align-items: flex-start;
	}

	.u-column {
		@include vue-flex;
		flex: 1;
		flex-direction: column;
		height: auto;
	}
}
// 滑动分类
.tabs-content {
	white-space: nowrap;
	.tab-item {
		min-height: 90rpx;
		display: inline-block;
		margin: 0 10rpx;
		padding: 0 20rpx;
		.tab-title {
			font-size: 28rpx;
			font-weight: 600;
			color: #333333;
		}
		.title-active {
			color: #a8700d;
		}
		.tab-des {
			font-size: 22rpx;
			font-weight: 400;
			color: #999999;
			text-align: center;
		}
		.des-active {
			background: linear-gradient(90deg, #e9b461, #eecc89);
			border-radius: 15rpx;
			padding: 2rpx 10rpx;
			color: #ffffff;
		}
	}
}
</style>
